The 29-year-old actress turned heads on the red carpet at the Captain America: The Winter Soldier premiere — her first appearance since the news broke that she is pregnant.

Scarlett debuted her tiny baby bump at the Captain America premiere

She dressed her curves in a lacy Giorgio Armani Prive top and skirt and smiled brightly for the cameras as she arrived for the premiere of the film. As well as a blossoming bump, Scarlett was also rocking her beautiful Art Deco-style engagement ring, which she proudly showcased as she posed for photographs.

Scarlett is yet to confirm that she is expecting her first baby with French fiancé Romain Dauriac. But Marvel Studios President of Production Kevin Feige was less tight-lipped during a recent interview with Collider.com.

Scarlett also showed off her beautiful art deco engagement ring

"Well my first reaction was I was very happy for her and very excited for her," he said of Scarlett's pregnancy news.

"My second reaction was we've got to move some pieces on the chess board around. But we didn't change the script at all, which is sort of the most important thing for us in terms of the storyline," he said of The Avengers: Age of Ultron script.

"I think the goal is for us to sit here talking about the fact that you would never know that Black Widow was pregnant during the filming of the movie when you see the final version of Avengers 2."

Scarlett posing with her co-stars at the screening

Similarly Jon Favreau, Scarlett's director and co-star in the upcoming comedy Chef, told E! this week that he thought the actress will make a great mother.

"She'll be wonderful," he confirmed. "She's one of my favourite people because she's smart, she's talented and she's really down to earth and a hard worker.

"I like a hard worker. She really did a lot of work to train to play Black Widow (in the Avengers movies). She's always pleasant to be around and she's got really good instincts about scenes. She helped me on Chef, she helped me a lot with the script and her character. She's good people."